Irradiation lamp system

ABSTRACT

An irradiation system comprises at least three lamp circuits of the gas vapor type connected electrically in parallel to an alternating current voltage source, each lamp circuit includes an impedance connected in series with the lamp, and each of the two outer lamp circuits is connected with the intermediate lamp circuit by a bridge located between the lamp and its impedance. Each bridge includes a thyristor and a trigger circuit therefor and a current circuit each of which contains a high-ohmic relay having contact means operable to actuate indicators for the lamps to show their respective operating conditions.

United States Patent [191 Muz [111 3,821,595 June 2, 1974 IRRADIATION LAMP SYSTEM [75] Inventor: Edwin Muz, Muhlbach, Germany [73] Assignee: BBC Brown Boveri & Company Limited, Baden, Switzerland 22 Filed: Apr. 2, 1973 21 Appl.No.:346,821

[30] Foreign Application Priority Data Apr. 7, 1972 Germany 2216722 [52] US. Cl 315/129, 315/250, 315/294, 315/282 [51] Int. Cl. H0lj l/60, H05b 4/16 [58] Field of Search 315/129, 130, 131, 132,

[56] References Cited UNITED STATES PATENTS 2,310,743 2/1943 Moss 315/294 X 3,526,808 9/1970 Michaelis 315/294 X Primary Examiner-Nathan Kaufman Attorney, Agent, or Firm-Pierce, Scheffler & Parker 1 ABSTRACT erable to actuate indicators for the lamps to show their respective operating conditions.

3 Claims, 2 Drawing Figures IRRADIATION LAMP SYSTEM The present invention relates to an irradiation system of the type wherein several lamps, especially luminous lamps in the form of radiation units, can be operated simultaneously.

An irradiation system, especially for cosmetic purposes, has previously been proposed, utilizing several appropriate lamps, serving as sources of ultra-violet radiation, and which are arranged under a common reflector, thus attaining a proper mixture of the various spectral factors, radiated by the different lamps. Provision has also been made to combine several reflectors, so equipped, into a system which will cover and illuminate a larger area, whereby the individual intensities of the lamps, arranged under the several reflectors, will form a uniform total intensity and fill the large area to be irradiated uniformly with a well mixed radiation.

There is further known an irradiation apparatus wherein is provided as a radiation unit, at least one discharge lamp in the form of a mixed vapor lamp, its radiation characteristic being adjustable in dependence upon the wall temperature of the discharge vessel. Specifically, in the case of a wall temperature of the vessel higher than approximately 500C, the mixed vapor lamp has the characteristic of a metal halide lamp, whereas in the case of a vessel wall temperature lower than approximately 500C, it has a characteristic of a high-pressure mercury vapor lamp. The setting of the wall temperature of the discharge vessel, which determines the proportion of the radiation factors relative to each other, is accomplished preferably by means of the electric power converted within the mixed vapor lamp; i.e. this power is utilized for pre-selection and setting of the operating mode of the mixed vapor lamp.

Since the operating mode of this known irradiation apparatus depends upon the electric power converted within the apparatus, a reliable control of this power becomes an absolute necessity. Especially, when several of the above-mentioned mixed vapor lamps are combined to form a larger system, as discussed above, there exists a requirement for a precise control of the lamps and for monitoring their working conditions.

The object of the present invention is to provide an improved circuit arrangement by which reliable operation of several of these lamps simultaneously can be obtained.

This objective is attained in that each lamp is connected in series with an impedance, whereby several of these series lamps-impedance circuits are combined in parallel, andwherein adjacent parallel branches, at a point between the corresponding lamps and the impedances, are each connected with each other by a bridge,

the bridge consisting of a thyristor and trigger circuit, and by a current path which includes therein a high ohmic relay. The novel solution proposed by the invention is particularly distinguished by the fact that it becomes possible to control three lamps by only two thyristors and two trigger circuits, where not the total power load, but only the change in power is regulated by the pha'se-bias-controlled thyristors which are connected between the lamps and the impedances always fully utilized power-wise. In this manner, there is increased very advantageously the electric power output of one lamp of the jointly operated lamp system, and there is lowered the electric power output of the other lamps. The current paths, or circuits, which include the high-ohmic relays between the adjacent paralleled lamp branches, additionally proposed by the invention, do not only serve to indicate a non-ignition, or subsequent extinction of any corresponding lamp, but will also indicate at a control desk, which is not restricted to location at the place where the lamps operate, or the location of the impedances, if and when one of the lamps has an insufficient arc voltage, or requires an excessive period of time to attain its working pressure.

Additional advantageous details of the invention are included in the following description of a preferred embodiment of the invention and the accompanying drawings wherein:

F IG. l is a circuit arrangement for a lamp system with three lamps operating in parallel; and

FIG. 2 is a schematic illustration of the contact systems of the high-ohmic relays which are utilized, and which form a part of the circuit illustrated in FIG. 1.

With reference now to FIG. 1, a lamp system utilizing three luminous gas lamps l, 2 and .3 such as those of the mixed vapor type is illustrated. Each lamp includes an impedance in the form of an inductive choke coil 4, 5 and 6, respectively designed for mean power and connected in series therewith, and the three lamps circuits are arranged electrically in parallel and connected to a voltage supply source terminals S, S1.

Adjacent parallel lamp circuit branches 1-4, 2-5 and 3 6 are each connected with one another by means of bridges 7 and 8, respectively, the bridge 7 being located between lamps ll, 2 and impedances 4, 5 and bridge 8 between lamps 2, 3 and impedances 5, 6. Bridge 7 is composed of a trigger circuit 10 which controls the conduction of a phase-bias-controlled thyristor 9, and bridge 8 is composed of a trigger circuit 12 which controls conduction of a phase-bias-controlled thyristor 11. The thyristors 9 and 11 are located within the bridges 7 and 8 respectively in such manner that the current can flow only from the outer parallel lamp branches containing lamps l and 3, respectively, to the centerlamp branch with the lamp 2, and can do so only when the thyristors 9 or 111 are opened to the current flow by pulses arriving from the trigger circuits 10 or 12, respectively. During these periods when thyristors 9 or 11 are open, the full current, but limited by impedances 4i, 5 and 6 will flow to lamp 2, thus offering an electric power to lamps l or 3 which is lower in the temporal mean, and to the lamp 2 an electric power which is higher, thereby attaining a regulating ratio of at least 1 3. r

In this manner it becomes possible to control the electric power of lamps ll, 2 or 3, as desired so that these lamps, if they are constituted by those of the mixed vapor type, which are used primarily for cosmetic purposes, will produce ultra-violet light of variable spectral composition.

The lamps 1, 2 and 3 can also be of the halide vapor type, their spectrum being variable within certain limits in relation to their electric output for the purpose of adjusting the color temperature of the radiated light, such lamps to be used, for example, in connection with television cameras, or the lamps can be in the form of lowpressure lamps or the like where the electric power determines their brightness.

ln order to monitor the working conditions of the lamps l, 2, 3 and for the purpose of indicating these conditions at a control desk which is not restricted as to location where the lamps themselves operate, or the location of the impedances 4, 5, 6, there are provided, as illustrated particularly by FIG. 2, additional current circuits 13, 14 which connect the parallel branches between the lamps and the impedances, each containing a high-ohmic relay 15, 16 respectively. Relay includes one throw-over contact 15 while relay 16 includes two throw-over contacts 16 and 16 which are always actuated simultaneously. Relays contacts 15, 16' and 16" are interconnected in the manner illustrated in FIG. 2, with a control lamp 17, indicating proper operation, provided in addition to the indicators 1a, 2a and 3a, assigned to the respective lamps 1, 2 and 3.

When all three lamps 1, 2 and 3 ignite, no significant difference in potential will arise across the coils of the relays 15 and 16 in the case of proper operation, the throw-over contacts 15', 16' and 16" will therefore each remain at their respective positions of rest a, and control lamp 17 will light up. However, if one-of the vapor lamps fails to ignite, or goes out after ignition, an

a.c. voltage representative of the value of the lamp voltage, arises across the corresponding relay, with the result that the affected relay contacts switch over, so that the proper indicator lamp will light up.

For example, if lamp 1 fails, due to non-ignition or extinction, the throw-over contact 15 of relay 15 will move from its position of rest a into an active position b and causes, by way of the throw-over contact 16" of relay 16 which remains at its position of rest a, the indicator lamp 1a to light up. If lamp 3 becomes defective, the throw-over contact 16 of relay 16 will move from its position of rest a into an active position b, and will activate the indicator lamp 3a by way of throwover switch contact 15 which remains in its position of rest a. If lamp 2 becomes defective, its indicator lamp 2a becomes activated, and will light up, by way of throw-over relay contacts 16" and 15', both being in their active positions b because in this case, both relays 15 and 16 have a.c. voltage applied across them.

l claim:

1. An irradiation system comprising at least three lamps of the luminous gas type, an impedance for and connected in series with each of said lamps to form a lamp circuit, means connecting said lamp circuits electrically in parallel to an alternating current voltage source, and bridges respectively interconnecting adjacent lamp circuits between the lamp and impedance, each said bridge comprising a thyristor and a trigger circuit therefor and a current circuit comprising a highohmic relay, said thyristors being oppositely poled such that current can flow through them only in the direction from the outer two lamps circuits towards the intermediate lamp circuit.

2. An irradiation system as defined in claim 1 wherein one high-ohmic relay includes one throw-over contact and another relay includes two throw-over contacts actuated simultaneously.

3. An irradiation system as defined in claim ll wherein one high-ohmic relay includes one throw-over contact and a second such relay includes first and second throwover contacts actuated simultaneously, a group of first indicators provided respectively for said lamps to show their respective operating condition, a second indicator common to all of said lamps to show a proper operating condition of all lamps, and means connecting said. indicators to an energizing source through the throw-over contacts of said relays, the indicator of the first group for one lamp being connected to its energizing source via the rest position of the second throw-over contact of said second relay and the active position of the throw-over contact of said first relay, the indicator of the first group for a second lamp being connected to its energizing source via the second throw-over contact of said second relay in its active position and the throw-over contact of said first relay in its active position, the indicator of the first group for a third lamp being connected to its energizing source via the first throw-over contact of said second relay in its active position and the throw-over contact of said first relay in its rest position, and said second indicator being connected to its energizing source via the first throw-over contact of said second relay in its rest position and the throw-over contact of said first relay in its rest position. 

1. An irradiation system comprising at least three lamps of the luminous gas type, an impedance for and connected in series with each of said lamps to form a lamp circuit, means connecting said lamp circuits electrically in parallel to an alternating current voltage source, and bridges respectively interconnecting adjacent lamp circuits between the lamp and impedance, each said bridge comprising a thyristor and a trigger circuit therefor and a current circuit comprising a high-ohmic relay, said thyristors being oppositely poled such that current can flow through them only in the direction from the outer two lamps circuits towards the intermediate lamp circuit.
 2. An irradiation system as defined in claim 1 wherein one high-ohmic relay includes one throw-over contact and another relay includes two throw-over contacts actuated simultaneously.
 3. An irradiation system as defined in claim 1 wherein one high-ohmic relay includes one throw-over contact and a second such relay includes first and second throw-over contacts actuated simultaneously, a group of first indicators provided respectively for said lamps to show their respective operating condition, a second indicator common to all of said lamps to show a proper operating condition of all lamps, and means connecting said indicators to an energizing source through the throw-over contacts of said relays, the indicator of the first group for one lamp being connected to its energizing source via the rest position of the second throw-over contact of said second relay and the active position of the throw-over contact of said first relay, the indicator of the first group for a second lamp being connected to its energizing source via the Second throw-over contact of said second relay in its active position and the throw-over contact of said first relay in its active position, the indicator of the first group for a third lamp being connected to its energizing source via the first throw-over contact of said second relay in its active position and the throw-over contact of said first relay in its rest position, and said second indicator being connected to its energizing source via the first throw-over contact of said second relay in its rest position and the throw-over contact of said first relay in its rest position. 